Flying squirrels are small, highly arboreal rodents found across North America and Eurasia, easily distinguished by their unique ability to glide. They are strictly nocturnal, confining their activity to the hours between dusk and dawn. This specialized timing is a fundamental biological necessity that shapes their behavior and physical adaptations.
Nocturnal Habits and Biological Timing
The decision to be active only at night is a primary mechanism for predator avoidance, especially from diurnal raptors like hawks. By remaining hidden in tree cavities or dense nests until after sunset, the squirrels escape the notice of daytime predators.
This nocturnal lifestyle is supported by a biological adaptation: their unusually large, dark eyes. These eyes are structured to maximize light gathering, providing the vision needed to navigate the dark forest canopy. Flying squirrels typically begin their nightly activity shortly after sunset. Their active period is dedicated to foraging and movement, and they generally return to their nests before sunrise.
Gliding Mechanics and Preferred Habitats
The flying squirrel’s movement is defined by the patagium, a furry membrane stretching from the wrist of the front limb to the ankle of the hind limb. This specialized skin flap acts like a parachute and an airfoil, allowing the rodent to glide, rather than truly fly, from one treetop to another. The squirrel controls its direction and speed by adjusting the tension of the patagium and using its flattened tail as a rudder.
The need for gliding dictates their preferred environment: mature, heavily canopied forests. These habitats provide the necessary height for launching and the dense arrangement of trees for sequential glides, sometimes covering distances of over 100 feet in a single descent. Furthermore, these mature forests offer abundant natural tree cavities, which the squirrels use as insulated dens for resting during the day and raising their young.
Nightly Foraging and Diet
The primary purpose of the flying squirrel’s nightly excursions is foraging, made efficient by their gliding ability which allows them to cover a wide area of the forest canopy. They are omnivores with a varied, seasonal diet, consuming nuts, seeds, fruits, insects, and occasionally bird eggs.
A key component of their diet is fungi, including subterranean varieties known as truffles. When consumed, the spores pass through their digestive system unharmed and are deposited elsewhere through their droppings. This behavior makes flying squirrels important agents in the dispersal of mycorrhizal fungi, which are beneficial to tree health.